Expander ring for trawl nets



May 12, 1964 Filed Feb. 18, 1963 F. J. LUKETA EXPANDER RING FOR TRAWL NETS 3 Sheets-Sheet 1 INVENTOR, AeA/wr a wear/4 F y/14.4% (Mag/1M y A rraeA/aya" ETA May 12, 1964 May 12, 1964 F. J. LUKETA EXPANDER RING FOR TRAWL NETS 3 SheetsSheet 3 Filed Feb. 18, 1963 INVENTOR. FRANK J. wk H4 rammed May 12, 1964 3,132,437 EXPANDER RING FOR TRAWL NETS Frank J. Luketa, 5567 Greenwood Ave., Seattle 3, Wash. Filed Feb. 18, 1963, Ser. No. 259,170 7 Claims. (Cl. 43-9) In a copending companion application of the same title bearing Serial No. 259,154, filed February 18, 1963, I have described a flexible expander ring formed of separate beads each fixed to the mesh about the entrance to a codend, at spacings such that they will come eiIectively into contact by the circumferential constriction attendant upon elongation of the mesh by an applied stress in use, and will thereby limit such construction and keep the entrance open. In another copending application of the same title, bearing Serial No. 259,150, filed February 18, 1963, I have described beads which are inherently elongatable, for the same purpose. In a third copending companion application of the same title, Serial No. 259,155, filed February 18, 1963, I have described beads which are joined by resiliently elastic connecting elements that are elongatable as the mesh elongates, and by their resilience restore the beads to their initial position upon relaxation, also for the same purpose.

This invention concerns a special form of connecting element between beads, according to said application, Serial No. 259,155, which depends upon resilience to a limited degree, but in which elongation is effected by sliding movement of a part or guide connected to one bead relative to a complemental part or guide connected to the next bead.

The object of the present invention is to provide a bead assembly for a flexible expander ring which is in its details different from those of the other applications mentioned, and which possess certain advantages of uniformity in manufacture.

FIGURE 1 is an isometric view, partly broken away, of a bottom trawl net such as the present invention can be applied to.

FIGURE 2 is an exploded isometric view of two mutually complemental but actually identical beads and associated guide elements.

FIGURE 3 is a plan view, partly in section, of several beads fixed to a single surface of the mesh element, with the meshes relaxed, and FIGURE 4 is a like view, with the meshes stressed and elongated.

FIGURE 5 is a sectional view, substantially at the line 5-5 of FIGURE 3.

FIGURE 6 is an isometric view, similar to FIGURE 4, but with the beads fixed to each surface of the mesh.

FIGURE 7 is a sectional view similar to FIGURE 5, and exploded, showing the doubled form of FIGURE 6, and FIGURE 8 is a like view with the parts assembled.

FIGURE 9 is an exploded sectional view like FIG- URE 7, showing a slightly modified construction, and FIGURE 10 is an assembled sectional view thereof, similar to FIGURE 8.

Referring first to the general view, FIGURE 1, the net is illustrated as a bottom trawl net, although the in vention is applicable also to a midwater trawl net. As shown it comprises a codend 9 of mesh, a funnel 8 of mesh converging aft and leading to the open entrance to the codend, and curtains 7 diverging forwardly from the upper bosom 81 and joined at 80 to the forward side edges of the funnel. Sweep lines 82 diverge forwardly from the opposite ends of the lower bosom 83 to doors 5 at the opposite sides of and ahead of the net, and curtain lines 70, whereon the curtains hang, diverge forwardly from the opposite ends of the upper bosom to the doors. Towing warps 50 from the trawler (not shown) drag the doors and hence the net forwardly. Suspenders 2 of heavy mesh are located at each side -of the funnel. Their after ends are distributed part way about the entrance to the funnel, at the line 98, and their forward ends are gathered to a point. The sweep lines 82 are anchored at such points to the respective suspenders 2, and transmit the drag to the codend through the suspenders. These suspenders tend to constrict circumferentially under longitudinal stress, and this tendency is transmitted to the codend at its entrance.

In essence the present invention employs a mesh element which encircles and defines the entrance to the codend, which mesh is so oriented that it is elongatable under stress, and thereby is constricted circumferentially. Such mesh element may be the mesh of the codend or of the funnel. In the absence of an expander ring or its equivalent, the constriction might progress until the entrance is effectively closed, and fish gathered in the funnel could not enter and would eventually escape. By this invention beads are secured to the mesh while relaxed, but at sufliciently close spacings circumferentially that when the mesh is elongated under the normal stresses of use the beads come at least approximately into contact, and by substantial interengagement limit the circumferential constriction and hold the entrance open suificiently so that fish can always enter. Nevertheless, when the circle of heads is subjected to diametrally rather than circumferentially applied force, it will collapse. Such a diametrally applied force results from the flattening eflect of the mesh as it is wound upon a drum, and as subsequent windings press the mesh towards the drum. All this will be explained more fully hereinafter.

The expander ring is shown as supported by, the mesh, whether of the codend or of the funnel is immaterial, but somewhere in the vicinity of the line 98 where the funnel joins the codend. In the form shown herein it consists of two circles of beads 1, with the beads of one circle joined with alternate beads of the other circle by relatively slidable connecting means that are also resiliently flexible. The several beads are fixed to points of the mesh, w 'le the mesh is relaxed. When the elongation of the mesh, which is especially noticeable when suspenders 2 are used, cause circumferential constriction, the flexibility of the connecting means accommodates such constriction, and the relative slidability of the parts thereof accommodates elongation of the mesh. The beads come into contact, or approximately so, to limit constriction of the mesh at the entrance to the codend. The flexibility of the connecting means, which is especially augmented when they are elongated, permits flattening of the ring when wound on a drum. The individual parts of the beads and their connecting means are identical, and can be made in a single mold, hence inexpensively.

The basic form of the beads and their connecting means is shown in FIGURE 2. Each bead 1 takes the form of a round, flat disk, from which extend more or less radially the post 10 and the guide sleeve 11, relatively angularly disposed. The disk is alike at its opposite faces, and is shown as having four holes 12 arranged in a crossing pattern; see for example FIGURE 4. Bosses 12a stand up from its faces, surrounding the holes. The beads and their integral connecting means are conveniently molded of rubber, nylon, polypropylene, or other elastically resilient material, and since all are identical a single mold can be used for all of them. The posts 10 are a sliding fit within the sockets or sleeves 11.

At installation a suflicient number of elements 1, 10, 11 are assembled in sinuous form to surround the entrance to the codend 9, with its meshes relaxed and the elements themselves unflexed and relaxed. The beads 1 are then mounted upon the mesh individually, using for example four screws 4 passing through the four holes 12,

straddling each of the two bars of the mesh that cross at a given point beneath the bead, and threaded into a washer 3, which might be of the same material as the beads and their connecting elements. The bosses 12a and complemental bosses 3:: on the washer aiford space for the mesh 9, without binding. When all the beads are thus mounted, whether exteriorly or interiorly of the entrance is immaterial, the assembly with the relaxed mesh is as shown in FIGURE 3. The successive connecting members extend at wide angles, and are unflexed, and non-extended. The mesh, too, is unstressed and open of mesh. The beads 1 are widely separated, and are arranged in two circles about the entrance, i.e., in what may be termed a compound circle pattern.

Now when the mesh is of nylon thread and therefore somewhat elastic, and is stressed longitudinally it is constricted circumferentially. The points to which successive beads are secured are drawn close together laterally, and are separated by a greater distance longitudinally. Since the beads are fixed at such points, they move in the same manner. The greater longitudinal distance between them causes the guide posts 10 to slide outwardly within their sleeves 11. The flexibility of the units permits the posts and the sleeve of each unit to approach angularly. The heads I approach until they more or less come into contact, and thereby form two rings about the entrance, separated longitudinally. The result is somewhat as is shown in FIGURE 4. A point is reached where further constriction is prevented, and the entrance to the codend is held open.

Now if the mesh is wound upon a drum, the flexibility of the elements comprising the rings of beads permits the rings to flatten, removing any material obstruction to winding on the remainder of the coden When stress upon the mesh is relaxed, as it is when setting the net, the resilience of the elements that comprise the rings restores them to circular form, and allows the guide elements 19, 11 to retract one within the other.

In the form shown in FIGURES 3 to 5 the beads and their guide elements 10, 11 are applied only to one surface of the mesh. They can be applied to both surfaces thereof, and are so shown in FIGURES 6 to 9. Here, instead of the washer 3, the screws 4 are threaded into long sleeve-like nuts 40 which pass through holes 12 in one of the two heads 1, the screws 4 being received in the holes 12 of the other head. The bosses 12a hold the beads apart to prevent their pinching the net between the beads or as an alternative in lieu of bosses spacer sleeves 41 may be employed, each received at its ends in sockets 14 at the ends of the holes 12; see FIGURES 9 and 10.

The functioning of the doubled form is just the same as has been described for the single form. The doubled form in effect divides each bead into halves. This form results in a somewhat more rigid expander ring and in some fisheries may be preferred.

From the foregoing discussion of several typical embodiments of the present invention, other modifications and adaptations thereof will readily occur to those skilled in the art to which the invention is addressed, within the scope of the following claims.

I claim as my invention:

1. In a trawl net, a mesh element defining the entrance to a codend, and elongatable under stress, to be thereby constricted circumferentially, a plurality of beads each secured to the meshes of said element and distributed in a compound circle pattern about the entrance to partake of the circumferential and elongational movement of the points of the mesh to which they are secured, and at sufficiently close spacings for each bead to come approximately into contact with the beads adjacent thereto when the mesh is elongated under normal stress, and complemental guide means on each head in a circle and on adjacent beads in another circle, said guide means being interengaged and relatively movable longitudinally by elongation and relaxation of the mesh.

2. The combination of claim 1, in which the guide means are flexibly connected to their respective beads, for change of angle between them as the meshes constrict or relax.

3. The combination of claim 1, in which each bead is formed with a guide post and with an angularly displaced guide sleeve receiving the guide post of an adjacent bead, and constituting the complemental guide means.

4. The combination of claim 3, wherein the guide post and the guide sleeve of each bead are flexible, to accommodate their relative angular movement.

5. The combination of claim 1, wherein a plurality of beads are arranged interiorly of the codend entrance and a like number exteriorly thereof, and screws interconnecting the beads which are inside and outside, respectively, at each location, and arranged in a pattern to straddle the crossing bars of the mesh at such locations.

6. The combination of claim 5, including bosses outstanding from the beads, surrounding the screws, to atford space for reception of the mesh.

7. The combination of claim 6, wherein sockets are formed in the beads, surrounding the screws, and a spacer sleeve in said sockets, to afford further space for reception of the mesh.

References Cited in the file of this patent UNITED STATES PATENTS 3,018,581 Luketa Ian. 30, 1962 FOREIGN PATENTS 294,363 Germany Ort. 4, l9l6 

1. IN A TRAWL NET, A MESH ELEMENT DEFINING THE ENTRANCE TO A CODEND, AND ELONGATABLE UNDER STRESS,TO BE THEREBY CONSTRICTED CIRCUMFERENTIALLY, A PLURALITY OF BEADS EACH SECURED TO THE MESHES OF SAID ELEMENT AND DISTRIBUTED IN A COMPOUND CIRCLE PATTERN ABOUT THE ENTRANCE TO PARTAKE OF THE CIRCUMFERENTIAL AND ELONGATIONAL MOVEMENT OF THE POINTS OF THE MESH TO WHICH THEY ARE SECURED, AND AT SUFFICIENTLY CLOSE SPACINGS FOR EACH BEAD TO COME APPROXIMATELY INTO CONTACT WITH THE BEADS ADJACENT THERETO WHEN THE MESH IS ELONGATED UNDER NORMAL STRESS, AND COMPLEMENTAL GUIDE MEANS ON EACH BEAD IN A CIRCLE AND ON ADJACENT BEADS IN ANOTHER CIRCLE, SAID GUIDE MEANS BEING INTERENGAGED AND RELATIVELY MOVABLE LONGITUDINALLY BY ELONGATION AND RELAXATION OF THE MESH. 